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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

The effect of vascular bubbles on endothelial function

Nossum, Vibeke January 2003 (has links)
The purpose of the study was to: • Study the effect of vascular gas bubbles on the brain and lung • Study changes in the endothelial function caused by gas bubbles • Study the preventive effects of monoclonal anti-C5a antibody on functional changes caused by gas bubbles It is important to reveal any changes in the function of the endothelium caused by gas bubbles, as the endothelium probably plays an important role in the development of decompression sickness (DCS). Furthermore, we followed up previous studies using monoclonal anti-C5a antibody trying to prevent damages caused by gas bubbles. In order to prevent damages causes by gas bubbles and maybe prevent DCS, the mechanisms behind have to be revealed. This thesis is part of an ongoing project that for several years has tried to bring to light the “secrets” of DCS.
52

Mitochondria and Human Evolution

Ingman, Max January 2003 (has links)
Mitochondrial DNA (mtDNA) has been a potent tool in studies of the evolution of modern humans, human migrations and the dynamics of human populations over time. The popularity of this cytoplasmic genome has largely been due to its clonal inheritance (in Man) allowing the tracing of a direct genetic line. In addition, a comparatively high rate of nucleotide substitution facilitates phylogenetic resolution among relatively closely related individuals of the same species. In this thesis, a statistically supported phylogeny based on complete mitochondrial genome sequences is presented which, for the first time, unambiguously places the root of modern human mitochondrial lineages in Africa in the last 200 thousand years. This conclusion provides strong support for the “recent African origin” hypothesis. Also, the complete genome data underline the problematic nature of traditional approaches to analyses of mitochondrial phylogenies. The dispersal of anatomically modern humans from the African continent is examined through single nucleotide polymorphism (SNP) and sequence data. These data imply an expansion from Africa about 57 thousand years ago and a subsequent population dispersal into Asia. The dispersal coincides with a major population division that may be the result of multiple migratory routes to East Asia. Also investigated is the question of a common origin for the indigenous peoples of Australia and New Guinea. Previous studies have been equivocal on this question with some presenting evidence for a common genetic origin and other proposing separate histories. Our data reveals an ancient genetic link between Australian Aborigines and the peoples of the New Guinea highlands.
53

Routine based recording of adverse eventsduring anaesthesia : application in quality improvement and safety

Fasting, Sigurd January 2003 (has links)
No description available.
54

Rectal cancer treatment in Norway - standardisation of surgery and quality assurance

Wibe, Arne January 2003 (has links)
The main purpose of the present work was to evaluate the efforts taken by the Norwegian surgical community in order to promote and enhance the standards of rectal cancer treatment on a national level, in particular: - to examine the outcome of rectal cancer surgery following implementation of total mesorectal excision as the standard rectal resection technique - to explore the prognostic impact of the circumferential resection margin on local recurrence, distant metastases and overall survival following mesorectal excision - to evaluate the oncological outcomes following mesorectal excision of cancer of the lower rectum, particularly the rates of local recurrence and overall survival for patients with tumours in this areas - to illustrate the influence of a rectal cancer registry as a quality control instrument on outcome of rectal treatment, and furthermore, to investigate the rates of postoperative mortality, anastomic leakage, local recurrence (LR) and overall survival related to hospital caseload among Norwegian hospitals during implementation of mesorectal excision.
55

Phylogeographic Structure and Genetic Variation in Formica Ants

Goropashnaya, Anna January 2003 (has links)
The aim of this thesis is to study phylogeny, species-wide phylogeography and genetic diversity in Formica ants across Eurasia in connection with the history of biotic responses to Quaternary environmental changes. The mitochondrial DNA phylogeny of Palaearctic Formica species supported the subgeneric grouping based on morphological similarity. The exception was that F. uralensis formed a separate phylogenetic group. The mitochondrial DNA phylogeny of the F. rufa group showed the division into three major phylogenetic groups: one with the species F. polyctena and F. rufa, one with F. aquilonia, F. lugubris and F. paralugubris, and the third one with F. pratensis. West-east phylogeographic divisions were found in F. pratensis suggesting post-glacial colonization of western Europe and a wide area from Sweden to the Baikal Lake from separate forest refugia. In contrast, no phylogeographic divisions were detected in either F. lugubris or F. exsecta. Contraction of the distribution range to a single refugial area during the late Pleistocene and the following population expansion could offer a general explanation for the lack of phylogeographic structure across most of Eurasia in these species. Sympatrically distributed and ecologically similar species F. uralensis and F. candida showed clear difference in the phylogeographic structure that reflected difference in their vicariant history. Whereas no phylogeographic divisions were detected in F. uralensis across Europe, F. candida showed a well-supported phylogeographic division between the western, the central and the southern group. In socially polymorphic F. cinerea, the overall level of intrapopulation microsatellite diversity was relatively high and differentiation among populations was low, indicating recent historical connections. The lack of correspondence between genetic affinities and geographic locations of studied populations did not provide any evidence for differentiating between alternative hypotheses concerning the directions and sources of postglacial colonization of Fennoscandia.
56

Evolutionary Studies of the Mammalian Y Chromosome

Hellborg, Linda January 2004 (has links)
Sex chromosomes are useful in elucidating the evolutionary factors affecting diversity and divergence. In particular, Y chromosome analyses may complement studies using mitochondrial DNA for inferring sex-specific population genetic processes. Y chromosome studies have been scarce due to limited access to genetic markers and the dynamic evolution of Y. Conserved Y-specific primers that could amplify a diverse set of mammalian species were developed from comparison of gametologous X and Y sequences. Y-specific sequence, generally more than one kb, was amplified for all 20 species examined. Intraspecific diversity on mammalian Y was found to be reduced even when male-biased mutation rate and effective population size were corrected for. A number of factors can cause this low variation on Y of which selection on a haploid chromosome seems most important. The field vole (Microtus agrestis), a common and well-studied small mammal in Eurasia, was examined for X and Y variability. Earlier studies on mtDNA had shown that the field vole is separated in two distinct lineages in Europe. The X and Y chromosome sequences confirmed the deep split and suggested that the two lineages of field vole should be reclassified as two separate species. Two distinct Y chromosome haplogroups were found in modern European cattle, distributed among breeds according to a north-south gradient. Ancient DNA analysis of European aurochsen showed the northern haplogroup to be the most common, possibly indicating local hybridization between domestic cows and wild aurochs bulls in Europe.
57

Strategies for Identification of Susceptibility Genes in Complex Autoimmune Diseases

Prokunina, Ludmila January 2004 (has links)
Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are complex autoimmune diseases affecting 0.05-2% of the population worldwide. Genetic studies detected linkage with SLE in the 2q37 region, and intensive family-based and case-control association studies in several populations identified that allele A of the SNP PD-1.3 located in the immunoreceptor PDCD1 (PD-1) gene, increases risk of the disease by 2.6-fold in Caucasians (p<0.00001) and by 3.5-fold in Mexicans (p=0.0009). The same allele was found to be a risk factor for lupus nephritis, a severe clinical manifestation of SLE. In Swedish and European-American females with SLE, patients with the allele A had nephritis 1.8 times (p=0.01) more often than patients with allele G . Moreover, the allele A was also found 1.8 times (p=0.005) more often in RA patients, negative for the known risk-factors, rheumatoid factor and the shared epitope, than in other groups of patients and controls. Functional studies demonstrated that the mechanism behind the SNP PD-1.3 is related to the disruption of the binding site for RUNX transcription factors in the regulatory region. Expression of the PD-1 and RUNX genes was altered in the activated T cells of SLE patients compared to controls. The Tumor Necrosis Factor Receptor 2 (TNFR 2) gene was studied as a second candidate gene for both SLE and RA. The results of our studies in SLE and RA patients and controls from Sweden and Mexico do not support the association of the polymorphism TNFR 2 M196R with these diseases. Other polymorphisms in this gene and other genes in this region should therefore be studied.
58

Molecular Genetic Studies of Genes Predisposing for Glaucoma / Molekylärgenetiska studier av gener som predisponerar för glaukom

Jansson, Mattias January 2004 (has links)
Glaucoma is one of the leading causes of visual impairment in the world. In glaucoma, the patient’s peripheral vision is lost due to progressive and irreversible deterioration of the retinal ganglion cells and atrophy of the optic nerve. The effect on the visual field is gradual and painless, and the progression so slow, that the patient may not notice until a substantial part of the visual field is lost. If left untreated, glaucoma can lead to blindness. In this thesis, genes associated to glaucoma have been analysed in Swedish patients with primary open angle and exfoliative glaucoma. The genes studied were MYOC, oculomedin, GSTM1 and OPTN. The coding sequence of MYOC was analysed and mutations were found in 1% of the primary open angle glaucoma patients. Additionally, a predisposing variant was found in 1% of the patients as well as in 0.5% of the controls. No disease-associated variation was found in the exfoliative glaucoma cases. Mutations were also found in two families affected by glaucoma. The coding sequence of oculomedin was analysed, but none of the variants found were classified as disease causing in either patient group. GSTM1 was analysed for its presence in the patients. No association could be found for either hetero- or homozygous deletions. The coding sequence and haplotype distribution of OPTN was analysed. None of the variants found were classified as disease causing and none of the haplotypes were associated to the disease in either patient group. There are just a few per cent of the Swedish primary open angle glaucoma patients with genetic variation associated to disease, in the genes analysed in this study. No association to exfoliative glaucoma was found. This indicates heterogeneity in the genetics of glaucoma when different subtypes and different populations are compared. Likely, there are genes still to be identified.
59

Immunoglobulin Gene Analysis in Chronic Lymphocytic Leukemia : Characterization of New Prognostic and Biological Subsets

Tobin, Gerard January 2004 (has links)
Recent studies have shown that the somatic mutation status of the immunoglobulin (Ig) VH genes can divide chronic lymphocytic leukemia (CLL) into two prognostic subsets, since cases with mutated VH genes display superior survival compared to unmutated cases. Biased VH gene usage has also been reported in CLL which may reflect antigen selection. We performed VH gene analysis in 265 CLL cases and confirmed the prognostic impact of the VH mutation status. Preferential VH gene usage was also demonstrated in both the mutated and unmutated subset. Interestingly, CLL cases rearranging one particular VH gene, VH3-21, displayed poor outcome despite that two-thirds showed mutated VH genes. Many of the VH3-21 cases expressed λ light chains, rearranged a Vλ2-14 gene, and had homologous complementarity determining region 3s (CDR3s), implying recognition of a common antigen epitope. We believe that the VH3-21 subset comprises an additional CLL entity. To further explore the B-cell receptors in CLL, we analyzed the VH gene rearrangements and, specifically, the heavy chain CDR3 sequences in 346 CLL cases. We identified six new subgroups with similar HCDR3 features and restricted VL gene usage as in the VH3-21-using group. Our data indicate a limited number of antigen recognition sites in these subgroups and give further evidence for antigen selection in the development of CLL. Different cutoffs have been suggested to distinguish mutated CLL in addition to the 2% cutoff. Using three levels of somatic mutations, i.e. <2%, 2-5% and >5%, we divided 323 CLLs into subsets with divergent survival. This division revealed a low-mutated subgroup (2-5%) with inferior outcome that would have been masked using the traditional 2% cutoff. A 1513A/C polymorphism in the P2X7 receptor gene was reported to be more frequent in CLL, but no difference in genotype frequencies was revealed in our 170 CLL cases and 200 controls. However, CLL cases with the 1513AC genotype showed superior survival than 1513AA cases and this was in particular confined to CLL with mutated VH genes. In summary, we could define new prognostic subgroups in CLL using Ig gene rearrangement analysis. This also allowed us to gain insights in the biology and potential role of antigen involvement in the pathogenesis of CLL.
60

Homeopathy in the prevention of upper respiration tract infections in children

Steinsbekk, Aslak January 2005 (has links)
The aim of this thesis is to explore why parents bring their children to homeopaths and to investigate the effect of homeopathic treatment for prevention of upper respiratory tract infections (URTI) in children. The reason for doing studies on this is that there has been a nearly threefold increase in the proportion of children among patients visiting Norwegian homeopaths. This raised the question of why it is so. Furthermore, recurrent respiratory complaints are a main reason why child patients consult homeopaths. This raised the question of the effect of homeopathic treatment in this patient group, because there is very little research on this. The thesis builds on four different studies conducted between August 2002 and June 2004. Parents of nine children that recently had been to a homeopath for the first time were interviewed to explore why parents take their children to homeopaths. All parents had been to a medical doctor before consulting the homeopath. It was the experiences with conventional medical treatment that led the parents to look for alternatives. The reasons were that 1) the parents did not want to give the medication prescribed by the doctor, 2) they wanted treatment while waiting for a problem to be assessed, 3) they did not want to continue to use the prescribed medication, 4) they stopped taking conventional medication due to side effects or 5) they were not offered any treatment by the medical doctor. The parents would consult a medical doctor if they felt insecure about the health conditions of the child and would visit a homeopath when they felt that the situation was clarified. There are parents who take their child to homeopaths despite not understanding or having belief in whether ultramolecular homeopathic medicines can have effects. One hundred and sixty-one children who had been diagnosed with an URTI by a medical doctor were recruited to participate in a trial on the effect of treatment by homeopaths for prevention of URTI in children. The children were randomly allocated to two groups. One group received an appointment immediately with one of five homeopaths who treated the patients as they do in their everyday practice. The other group (control) got such treatment after three months. The occurrence of URTI judged by the parents were significantly lower among those treated immediately by homeopaths (median 8 days in three months) compared to the control group who used self-selected conventional health care (median 13 days) (p=0.006). Homeopathic medicines are frequently used for self-treatment (over the counter-OTC). It is not known if the choice of the patient is the same, as a homeopath would have prescribed. A study was therefore conducted to explore if there can be developed indications for homeopathic medicines that facilitate that parents can chose the same medicine as a homeopath would prescribe for children with URTI. Firstly, data from a survey was used to find three medicines Calcarea carb, Pulsatilla and Sulphur that accounted for 60% of all prescription made by Norwegian homeopaths for children with URTI. Simplified constitutional indications for these medicines were developed and tested by comparing the choices of 70 parents with the prescription of eleven homeopaths. The parents were able to choose the same homeopathic medicine as homeopaths prescribed for 55% of the children. Two hundred and fifty-nine children who had been diagnosed with an URTI by a medical doctor were recruited to participate in a trial on the effect of one of three self-selected ultramolecular homeopathic medicines for prevention of URTI in children. The indications developed were used. The children was randomly allocated to receive either ultramolecular homeopathic medicine (C-30) or placebo. There was no difference in the occurrence of URTI judged by the parents among getting ultramolecular homeopathic medicine compared to those getting placebo (median 9 days in three months for both groups) (p=0.531). / Hensikten med denne avhandlingen er å undersøke hvorfor foreldre tar sine barn med til homøopat og å undersøke effekten av homøopatisk behandling i forebygging av øvre luftveisinfeksjoner (ØLI) hos barn. Bakgrunnen for de undersøkelsene som er gjort, er at det nesten er en tredobling i andelen barn blant pasienter hos homøopat. Dette utløste spørsmål om hvorfor det er slik. Videre er gjentatte luftveisplager en hovedårsak til at barn oppsøker homøopat. Fordi det er lite forskning på dette temaet ble spørsmålet om effekten av homøopatisk behandling i denne pasientgruppen også utløst. Avhandlingen bygger på fire ulike undersøkelser som er gjennomført mellom august 2002 og juni 2004. Foreldre til ni barn som nylig hadde vært hos homøopat for første gang ble intervjuet for å undersøke hvorfor foreldre tar sine barn med til homøopat. Alle foreldrene hadde vært hos lege før de kontaktet homøopaten, og det var erfaringer med legebehandlingen som fikk foreldrene til å søke alternativer. Årsakene var at foreldrene 1) ikke ønsket å gi den behandlingen lege foreskrev til barnet, 2) ønsket behandling mens barnet ventet på å bli ferdig utredet, 3) ønsket å avslutte bruken av de medisinene legen hadde foreskrevet for barnet, 4) opplevde at barnet fikk bivirkninger av behandlingen legen hadde gitt og 5) ikke ble tilbudt noen behandling hos legen. Foreldre oppsøker først lege når de er usikre eller bekymret for barnets helsetilstand. De oppsøker homøopat for behandling når dette er avklart. Det er foreldre som oppsøker homøopat med sine barn selv om de ikke forstår eller tror på effekten av homøopatiske medisiner (som kan være svært fortynnet). Ett hundre og sekstini barn som hadde vært til lege på grunn av en øvre luftveisinfeksjon ble rekruttert til å være med på en undersøkelse av effekten av behandling hos homøopat i forebyggingen av ØLI hos barn. Barna ble tilfeldig fordelt i to grupper. Barna i den ene gruppen fikk time med en gang hos en av fem homøopater som foreskrev homøopatisk behandling på vanlig måte. Den andre gruppen fikk slik behandling etter 3 måneder. Forekomsten av ØLI Hensikten med denne avhandlingen er å undersøke hvorfor foreldre tar sine barn med til homøopat og å undersøke effekten av homøopatisk behandling i forebygging av øvre luftveisinfeksjoner (ØLI) hos barn. Bakgrunnen for de undersøkelsene som er gjort, er at det nesten er en tredobling i andelen barn blant pasienter hos homøopat. Dette utløste spørsmål om hvorfor det er slik. Videre er gjentatte luftveisplager en hovedårsak til at barn oppsøker homøopat. Fordi det er lite forskning på dette temaet ble spørsmålet om effekten av homøopatisk behandling i denne pasientgruppen også utløst. Avhandlingen bygger på fire ulike undersøkelser som er gjennomført mellom august 2002 og juni 2004. Foreldre til ni barn som nylig hadde vært hos homøopat for første gang ble intervjuet for å undersøke hvorfor foreldre tar sine barn med til homøopat. Alle foreldrene hadde vært hos lege før de kontaktet homøopaten, og det var erfaringer med legebehandlingen som fikk foreldrene til å søke alternativer. Årsakene var at foreldrene 1) ikke ønsket å gi den behandlingen lege foreskrev til barnet, 2) ønsket behandling mens barnet ventet på å bli ferdig utredet, 3) ønsket å avslutte bruken av de medisinene legen hadde foreskrevet for barnet, 4) opplevde at barnet fikk bivirkninger av behandlingen legen hadde gitt og 5) ikke ble tilbudt noen behandling hos legen. Foreldre oppsøker først lege når de er usikre eller bekymret for barnets helsetilstand. De oppsøker homøopat for behandling når dette er avklart. Det er foreldre som oppsøker homøopat med sine barn selv om de ikke forstår eller tror på effekten av homøopatiske medisiner (som kan være svært fortynnet). Ett hundre og sekstini barn som hadde vært til lege på grunn av en øvre luftveisinfeksjon ble rekruttert til å være med på en undersøkelse av effekten av behandling hos homøopat i forebyggingen av ØLI hos barn. Barna ble tilfeldig fordelt i to grupper. Barna i den ene gruppen fikk time med en gang hos en av fem homøopater som foreskrev homøopatisk behandling på vanlig måte. Den andre gruppen fikk slik behandling etter 3 måneder. Forekomsten av ØLI var signifikant lavere hos de som fikk behandling hos homøopat med én gang (median 8 dager på tre måneder) sammenlignet med den andre gruppen som brukte standard behandling ved behov mens de ventet (median 13 dager) (p=0,006). Homøopatisk medisin brukes internasjonalt i stor grad til selvbehandling. Man vet ikke om pasientens eget valg av homøopatisk medisin er lik det en homøopat ville foreskrevet. Det ble derfor gjennomført en undersøkelse av om det kan utvikles beskrivelser for indikasjoner for homøopatiske medisiner som gjør at foreldre kan velge samme medisin som en homøopat foreskriver for barn med ØLI. Først ble det funnet fram til tre medisiner, Calcarea carb, Pulsatilla og Sulphur som homøopater i Norge foreskriver til 60% av barn med ØLI. Så ble det utviklet indikasjoner for disse tre medisinene som ble testet ut ved at valgene til 70 foreldre ble sammenlignet med foreskrivingen til 11 homøopater. Foreldrene valgte samme medisin som homøopaten for 55% av barna. To hundre og femtien barn som hadde vært til lege på grunn av en øvre luftveisinfeksjon ble rekruttert til å være med på en undersøkelse av effekten av en av tre selvvalgte homøopatiske medisiner i forebyggingen av ØLI hos barn. Indikasjonene som ble utviklet ble brukt. Barna ble tilfeldig fordelt til enten å få homøopatisk medisin eller placebo. Det var ingen signifikant forskjell i forekomsten av ØLI mellom de som fikk homøopatisk medisin sammenlignet med de som fikk placebo (median 9 dager på tre måneder i begge grupper) (p=0,531).

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